A compound having a structure represented by the general formula (1), such as luliconazole (in the general formula (1), R1═R2=chlorine atom), has excellent antimycotic activity, and it has been suggested that the compound may be applied to a treatment for a mycosis of the nail, which has been considered to be untreatable by external application (e.g., see Patent Document 1). Such preparation for treating the mycosis of the nail is desired to have an increased content of the compound represented by the general formula (1). However, because of its high crystallinity, solvents which can be used for producing a preparation containing the compound at a high concentration are very limited. That is, some solvents may cause disadvantages such as crystallization under a low temperature condition (such as 5° C.) and crystallization by application. In addition, in a solution of a compound represented by the general formula (1) which has stereoisomers, such as luliconazole, an stereoisomer such as an SE form is easily formed in some cases, and as solvents capable of preventing formation of such stereoisomers, only crotamiton, propylene carbonate, and N-methyl-2-pyrrolidone are known (e.g., see Patent Document 2). However, in some cases, blending of such solvents is restricted because of drug efficacy of the solvents, such as the anti-inflammatory effect of the solvents, and it has been desired to develop a novel solvent for a preparation of luliconazole or the like which substitutes for the solvents. In particular, in the case of a liquid preparation, the pharmacological effect significantly decreases by crystallization or the like, and hence such solubilization technology is an important factor for formulation. In addition, there may be a situation where a stereoisomer such as a Z form should be considered.
Lanoconazole (in the general formula (1), R1=hydrogen atom, and R2=chlorine atom), which is a compound represented by the general formula (1), is known as a useful antimycotic agent. However, also in the case of the compound, there are large problems in production technologies, such as crystallization caused by using the compound at a low temperature and decrease in the content caused by storage at a high temperature.
On the other hand, a ketone such as methyl ethyl ketone is widely used as a solvent excellent in solubilization ability. However, there is no known pharmaceutical preparation containing 1) a compound represented by the following general formula (1) and/or a salt thereof and 2) a ketone represented by the general formula (2).
(In the formula, R1 and R2 each independently represents a hydrogen atom or a halogen atom, and at least any one of R1 and R2 represents a halogen atom.)
(In the formula, R3 and R4 each independently represents an alkyl group or alkenyl group which may have an aromatic group, or an aromatic group, and the sum of the number of carbon atoms in R3 and R4 is 3 or more.)
Further, a hydroxyalkylbenzene such as benzyl alcohol or phenethyl alcohol is widely used as a solvent for solubilizing poorly-soluble components in the drug or quasi-drug field (e.g., see Patent Document 3). However, there is no example of the use of the hydroxyalkylbenzene for solubilization of the compound represented by the general formula (1) and/or the salt thereof. Moreover, there is no example of the use of the hydroxyalkylbenzene as a solvent for solubilization in a pharmaceutical composition containing the compound or the like and the ketone represented by the general formula (2).    [Patent Document 1] WO/2007/102241    [Patent Document 2] WO/2007/102242    [Patent Document 3] JP 2006-232856 A